Rugose Coral Caryophyllia Ambrosia
Period: Early Permian
L 13mm (.5in)
Unlike most corals, Caryophyllia ambrosia does not live in colonies. Rather, it lives a solitary life, attaching to the ocean floor and filter feeding to obtain nutrients. This specimen was found from the Toroweap Formation which is early Permian in age (about 275 million years ago) and was collected by Edward Schenk in 1936, from a site just north of Frenchman Mountain.
Photographer: Andy Cattoir
LAKE 1022
Brachiopod
Period: Early Permian
L 25mm (1 in.)
Brachiopods had two shells that hinged together similar to a clam, although brachiopods went extinct 252 million years ago at the end of the Permian period. This specimen was found in the Toroweap Formation which is early Permian in age (about 275 million years ago). It was collected by Edward Schenk in 1936, from a site just north of Frenchman Mountain.
Photographer: Andy Cattoir
LAKE 1023
Bryozoan
Period: Early Permian
L 25mm (1 in.)
Bryozoans are microscopic filter feeders that live in a colony, similar to coral. This specimen was found from the Toroweap Formation which is early Permian in age (about 275 million years ago) and was collected by Edward Schenk in 1936, from a site just north of Frenchman Mountain.
Photographer: Andy Cattoir
LAKE 1049
Coral Cladopora Disphyllum
Period: Middle to Late Devonian
L 32mm (1.25 in.)
This is a specimen of the colonial-dwelling coral Cladopora disphyllum. This specimen comes from the middle to late Devonian (385-358 million years ago) Sultan Formation. It was collected from the West Muddy Mountains by Edward Schenk in 1936.
Photographer: Andy Cattoir
LAKE 1057
Coral Cladopora Disphyllum
Period: Middle to Late Devonian
L 28mm (1.1 in.)
This block preserves the colonial-dwelling coral Cladopora disphyllum. This specimen comes from the middle to late Devonian (385-358 million years ago) Sultan Formation. It was collected from the West Muddy Mountains by Edward Schenk in 1936.
Photographer: Andy Cattoir
LAKE 1067
Coral Cladopora Disphyllum
Period: Early to Late Mississippian
L 203mm (8 in.)
This block contains a solitary type of coral, which would attach to the bottom of the ocean floor to filter feed. The specimen was found in the early to late Mississippian (358-325 million years ago) Redwall Limestone, and was collected by Edward Schenk in 1936 from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1080
Coral Zaphrentites Persimilis
Period: Early to Late Mississippian
L 31mm (1.2 in.)
This specimen is a solitary type of coral, which would attach to the bottom of the ocean floor to filter feed. It was found in the early to late Mississippian (358-325 million years ago) Redwall Limestone, and was collected by Edward Schenk in 1936 from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1154
Coral Zaphrentites Persimilis
Period: Early to Late Mississippian
L 31mm (1.2 in.)
This specimen is a solitary type of coral, which would attach to the bottom of the ocean floor to filter feed. This specimen was found in the early to late Mississippian (358-325 million years ago) Redwall Limestone. This specimen was collected by Edward Schenk in 1936, from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1187
Snail Straparollus Ophirensis
Period: Early to Late Mississippian
L 40mm (1.6 in.)
This is a specimen of the snail Straparollus ophirensis, which had a coiled shell with an elevated spire. It lived in the early to late Mississippian (358-325 million years ago) and was collected from the Redwall Limestone by Edward Schenk in 1936 from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1273
Coral Michelinia Expansa
Period: Early to Late Mississippian
L 55mm (2.1 in.)
This colonial coral, known as Michelinia expansa, lived in reef-forming groups. This specimen was found in the Redwall Limestone which is early to late Mississippian in age (358-325 million years ago). It was collected by Edward Schenk in 1936 from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1278
Spiriferid Brachiopod
Period: Early to Late Mississippian
L 40mm (1.6 in.)
This ocean-dwelling brachiopod had valves that articulated in an elongated zig-zag pattern, making it look somewhat like a wing. This specimen was collected from the Redwall Limestone which is early to late Mississippian in age (358-325 million years ago). It was collected from a site between Lake Mead and the Grand Canyon by Edward Schenk in 1936.
Photographer: Andy Cattoir
LAKE 1293
Syringopora Surcularia
Period: Early to Late Mississippian
L 71mm (2.8 in.)
This specimen of colonial coral is called Syringopora surcularia and was collected from the Redwall Limestone, which is early to late Mississippian in age (358-325 million years ago). It was collected from a site between Lake Mead and the Grand Canyon by Edward Schenk in 1936.
Photographer: Andy Cattoir
LAKE 1298
Colonial Coral Syringopora Surcularia
Period: Early to Late Mississippian
L 79mm (3.1 in.)
This specimen of colonial coral is called Syringopora surcularia and was collected from the Redwall Limestone, which is early to late Mississippian in age (358-325 million years ago). It was collected from a site between Lake Mead and the Grand Canyon by Edward Schenk in 1936.
Photographer: Andy Cattoir
LAKE 1309
Brachiopod Productus Crawfordsvillensis
Period: Early to Late Mississippian
L 83mm (3.3 in.)
This specimen of brachiopod is Productus crawfordsvillensis and was found in the Monte Cristo Group, which is early to late Mississippian in age (358-325 million years ago). All articulated brachiopods, including this form, went extinct at the end of the Permian (252 million years ago).
Photographer: Andy Cattoir
LAKE 1333
Crinoid Column
Period: Middle to Late Paleozoic
L 20mm (.75 in.)
This piece of a crinoid stem eroded from one of the limestone peaks around Lake Mead. The common name for crinoids is the sea lily. This name is derived from their appearance, with a stem that attaches to the ocean floor and a flower-like calyx. They are echinoderms, which means they're related to starfish and sea urchins. This specimen is from the Paleozoic period (350-270 million years ago), but crinoids still exist in the oceans today.
Photographer: Andy Cattoir
LAKE 1616
Trilobite Glossopleura Mckeei
Period: Middle to Late Paleozoic
L 20mm (.75 in.)
This specimen of the trilobite Glossopleura mckeei is encased in plaster. A trilobite is a small carnivorous ocean creature that scuttled along the ocean floor. This specimen was collected by 1940 in the area of Rampart Cave in the Grand Canyon. It was collected by Edward Schenk from the middle Cambrian age (515 million years ago) Bright Angel.
Photographer: Andy Cattoir
LAKE 1724
Cephalopod Nautiloid
Period: Late Mississippian to Early Permian
L 40mm (1.6 in.)
This cephalopod is an orthoceratid (straight-shelled) nautiloid, and was a benthic carnivore - similar to a modern day squid, but with a shell. This specimen was found in the late Mississippian to early Permian age (320-285 million years ago) Pakoon Limestone/Callville Formation. It was collected by Edward Schenk in 1938 from Iceberg Canyon, located in Eastern Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 1734
Vesiculophyllum Incrassatum Coral
Period: Late Mississippian to Early Permian
L 25mm (1 in.)
This specimen of Vesiculophyllum incrassatum was found in the Pakoon Limestone/Callville Formation, which is late Mississippian to early Permian in age (320-285 million years ago). It was collected by Edward Schenk in 1938 from Iceberg Canyon in the eastern part of Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 1817
Coral Vesiculophyllum Incrassatum
Period: Late Mississippian to Early Permian
L 97mm (3.8 in.)
This specimen of Vesiculophyllum incrassatum was found in the Pakoon Limestone/Callville Formation which is late Mississippian to early Permian in age (320-285 million years ago). It was collected by Edward Schenk in 1938 from Iceberg Canyon in the eastern part of Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 1821
Coral Zaphrentites Persimilis
Period: Early to Late Mississippian
L 33mm (1.3 in.)
This block contains a solitary type of coral, which would attach to the bottom of the ocean floor to filter feed. This specimen was found in the early to late Mississippian (358-325 million years ago) Redwall Limestone and was collected by Edward Schenk in 1936, from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 1832
Coral Vesiculophyllum Incrassatum
Period: Early to Late Mississippian
L 84mm (3.3 in.)
This specimen of Vesiculophyllum incrassatum was found in the Pakoon Limestone/Callville Formation which is late Mississippian to early Permian in age (320-285 million years ago). It was collected by Edward Schenk in 1938 from Iceberg Canyon in the eastern part of Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 1846
Productid Brachiopod
Period: Early Permian
L 99mm (3.9 in.)
This specimen of Productid brachiopod was collected by Edward Schenk in 1938 from the early Permian age (275-270 million years ago) Kaibab/Toroweap Formations in eastern Lake Mead NRA. It is among the group of brachiopods that went extinct at the end of the Permian (252 million years ago).
Photographer: Andy Cattoir
LAKE 1877
Productid Brachiopod
Period: Early Permian
L 99mm (3.9 in.)
This specimen of Productid brachiopod was collected by Edward Schenk in 1938 from the early Permian age (275-270 million years ago) Kaibab/Toroweap Formations in eastern Lake Mead NRA. It is among the group of brachiopods that went extinct at the end of the Permian (252 million years ago).
Photographer: Andy Cattoir
LAKE 2079
Snail Straporollus Subplanus
Period: Early to Late Mississippian
L 53mm (2 in.)
This is a specimen of the snail Straporollus subplanus. It lived in the early to late Mississippian (358-325 million years ago) and was collected from the Redwall Limestone by Edward Schenk in 1936, from a site between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 2087
Amphibian Metoposaur
Period: Early to Late Mississippian
L 43mm (1.7 in.)
This is a skull fragment from an early amphibian known as a metoposaur, which would have looked similar to a very large salamander. It is from the late Triassic Chinle Formation and lived around 213 million years ago. It was collected by Edward Schenk in 1938 from a location west of Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 2148
Trilobite Glossopleura Mckeei
Period: Middle Cambrian
L 76mm (3 in.)
This rock contains many fragmented segments of the trilobite Glossopleura mckeei. Trilobites were carnivorous creatures that scuttled along the ocean floor and resembled large roly-poly bugs. This specimen was found in the Bright Angel Shale which is mid-Cambrian in age (515 million years ago).
Photographer: Andy Cattoir
LAKE 2210
Ammonite
Period: Pennsylvanian
L 48mm (1.9 in.)
This fossil is currently unidentified and may be a new species of ammonite. Ammonites were similar to squid or nautiloids and live in coiled shells. This specimen was found in the Pakoon Limestone which is Pennsylvanian in age (323-300 million years ago), from a site northwest of Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 2304
Leaf Impression
Period: Late Cretaceous
L 84mm (3.3 in.)
This is an impression of a dicot leaf, which is a flowering plant. This specimen was collected from the late Cretaceous age (95 million years ago) Baseline Sandstone. It was collected by Edward Schenk between 1935-1937, from a locality east of the Valley of Fire State Park.
Photographer: Andy Cattoir
LAKE 2360
Gastropod
Period: Late Pliocene to Early Pleistocene
L 20mm (.8 in.)
This tightly coiled gastropod, identified as Helisoma tenue, would have lived in a fresh water lake in Southern Nevada about 2.8 million years ago during the late Pliocene to early Pleistocene Epochs.
Photographer: Andy Cattoir
LAKE 2427
Petrified Wood
Period: Late Triassic
L 203mm (8 in.)
This large piece of petrified wood comes from the late Triassic age (213 million years ago) Chinle Formation. This specimen was found at Lake Mead NRA and is from the same formation that preserves the giant logs of petrified wood seen at Petrified Forest National Park.
Photographer: Andy Cattoir
LAKE 2493
Crinoids A
Period: Middle to Late Paleozoic
This rock is full of crinoid segments and was collected near Temple Bar in Lake Mead NRA. The common name for crinoids is the sea lily. This name is derived from their appearance, with a stem that attaches to the ocean floor and a flower-like calyx - through which it feeds - at the top. They are echinoderms, which means they are related to starfish and sea urchins. This specimen is from the middle to late Paleozoic (350-270 million years ago), but crinoids still exist in the world's oceans today.
Photographer: Andy Cattoir
LAKE 2494_A
Crinoids B
Period: Middle to Late Paleozoic
This rock is full of crinoid segments and was collected near Temple Bar in Lake Mead NRA. The common name for crinoids is the sea lily. This name is derived from their appearance, with a stem that attaches to the ocean floor and a flower-like calyx - through which it feeds - at the top. They are echinoderms, which means they are related to starfish and sea urchins. This specimen is from the middle to late Paleozoic (350-270 million years ago), but crinoids still exist in the world's oceans today.
Photographer: Andy Cattoir
LAKE 2494_B
Reptile Tracks
Period: Early Permian
These tracks are identified as Chelichnus, and were made by an early mammal-like reptile that scampered across a sand dune environment. These tracks were made in the early Permian (280-275 million years ago), and this specimen was collected from the Coconino Sandstone between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 2499
Corals
L 140mm (5.5 in.)
Three genera of coral are preserved in this block: Zaphrentities, Michelinia, and Favosites. These corals would have been part of an ancient reef complex that existed in Southern Nevada 350 million years ago when the area was covered by an ocean.
Photographer: Andy Cattoir
LAKE 2500
Bryzoan
L 87mm (3.4 in.)
These bryozoans are very small to microscopic filter feeders that lived in a colony - in a manner similar to coral. This fan-like specimen is called a fenestrate bryozoan and would have been part of an ancient reef complex that existed in Southern Nevada 350 million years ago when the area was covered by an ocean.
Photographer: Andy Cattoir
LAKE 2506
Petrified Wood
Period: Late Triassic
L 75mm (2.9 in.)
This small piece of petrified wood comes from the late Triassic age (213 million years ago) Chinle Formation. This specimen was found at Lake Mead NRA and is from the same formation that preserves the giant logs of petrified wood seen at Petrified Forest National Park.
Photographer: Andy Cattoir
LAKE 2509
Palm Roots
L 78mm (3 in.)
This specimen of chert contains preserved elements of silica-replaced palm roots.
Photographer: Andy Cattoir
LAKE 2520
Snail
L 57mm (2.2 in.)
This is a cast of a high-spired snail. During the fossilization process, sediment (including fragmented elements of smaller ocean organisms), filled the void within the shell and preserved the cast of the snail as well as the small fossil fragments within the sediment.
Photographer: Andy Cattoir
LAKE 2529
Bird Tracks
Period: Early Miocene
L 305mm (12 in.)
These tracks were collected from the Early Miocene age (17-14 million years ago) Horse Spring Formation, Thumb Member, from a site within Lake Mead NRA. The tracks were left by a wading or shore bird as it walked across the wet sand along the shore of a freshwater lake.
Photographer: Andy Cattoir
LAKE 3712
Reptile Tracks
Period: Early Permian
L 72mm (2.8 in.)
These tracks are identified as Chelichnus,and were made by an early mammal-like reptile that scampered across a sand dune environment. These tracks were made in the early Permian (280-275 million years ago), and this specimen was collected from the Coconino Sandstone between Lake Mead and the Grand Canyon.
Photographer: Andy Cattoir
LAKE 3787
Concretion
L 62mm (2.4 in.)
This small nodule of chalcedony is an example of a concretion, which forms when layers of mud, sediment, or minerals collect around a small object, such as a stick or bone. The break pattern indicates that this concretion was broken open by a human, possibly a miner interested in finding valuable minerals, or an Indigenous person creating a tool.
Photographer: Andy Cattoir
LAKE 4111
Bird Tracks
Period: Early Miocene
L 222mm (8.75 in.)
These tracks were collected from the Early Miocene age (17-14 million years ago) Horse Spring Formation, Thumb Member, from a site within Lake Mead NRA. The tracks were left by a wading or shore bird as it walked across the wet sand along the shore of a freshwater lake.
Photographer: Andy Cattoir
LAKE 32104
Horse Jaw
Period: Pliocene
L 279mm (11 in.)
This mandible comes from a species of ancient horse known as Equussimplicidens, also called the Hagerman's Horse. It was slightly smaller than a modern horse, and lived during the Pliocene (3.5 million years ago). This specimen was found in Lake Mead NRA.
Photographer: Andy Cattoir
LAKE 32910
Columbian Mammoth Humerus
This leg bone of a Columbian mammoth was collected from river alluvium deposits from the Overton Arm of Lake Mead, by UNLV Professor Steve Rowland in 1983. The Columbian mammoth lived in North America between 1.5 million and 12,000 years ago.
Photographer: Andy Cattoir
Columbian Mammoth Humerus
Columbian Mammoth Tusk
This Columbian mammoth tusk was collected in 1991 from a site north of Echo Bay by a crew from Northern Arizona University. This piece of a tusk is still in the plaster jacket in which it was collected to protect the fossil. The crew also collected rib and other mammoth bone fragments at the same site.
Photographer: Andy Cattoir
Columbian Mammoth Tusk